Sucralose (4,1′,6′-trichloro-4,1′,6′-trideoxy-galactosucrose), a high-intensity sweetener made from sucrose, can be used in many food and beverage applications. Unlike many artificial sweeteners, sucralose can be used in cooking and baking with no loss of sweetening power.
Sucralose is generally made following the procedures set forth in U.S. Pat. No. 4,362,869; U.S. Pat. No. 4,380,476; U.S. Pat. No. 4,801,700; U.S. Pat. No. 4,950,746; U.S. Pat. No. 5,470,969; and U.S. Pat. No. 5,498,709. In all these procedures, one of the final steps in the synthesis is a deacylation followed by the crystallization of the sucralose. Laboratory scale methods for crystallizing sucralose have been described in U.S. Pat. No. 4,343,934; U.S. Pat. No. 5,141,860; U.S. Pat. No. 4,977,254; U.S. Pat. No. 4,783,526; U.S. Pat. No. 4,380,476; U.S. Pat. No. 5,298,611; U.S. Pat. No. 4,362,869; U.S. Pat. No. 4,801,700; and U.S. Pat. No. 4,980,463. As is described in many of these patents, the deacylation of the sucralose precursor is performed in methanol with a catalytic amount of sodium methoxide. After completion of deacylation, the resulting sucralose solution is contacted with an ion exchange resin to convert the residual sodium methoxide to methanol. The ion exchange resin is then removed and the volatile solvents and reaction byproducts are removed by co-distillation with water, which results in a solvent switch to water. The mixture is decolorized by contacting with activated carbon. The carbon is removed to provide a decolorized sucralose solution suitable for crystallizing sucralose. The sucralose solution is concentrated to about 55 weight percent sucralose (at about 50° C.). The crystallization is performed by reducing the temperature to about 22° C. and adding about 2 percent sucralose seed crystals. The crystals that form are separated from the mother liquor by centrifugation, then dried. The mother liquor that is separated from the crystals is added to the next batch just prior to decolorization.
Unfortunately, this process has a few drawbacks. The mother liquor can become acidic over time. In addition, the accumulation of impurities can interfere with the crystallization of sucralose, resulting in the need to periodically purge or discard the mother liquor. Crystalline sucralose, prepared as described above, generates minute amounts of hydrochloric acid, which reduces the shelf life of sucralose.
To overcome the shortcomings of existing sucralose and the products made from the sucralose, a new crystalline sucralose is provided. It is an object of the present invention to provide an improved crystalline sucralose composition that exhibits increased stability.